Briggs engine, no spark

RenegadeT

RenegadeT

no shirt,no shoes,no dice
Moderator
Joined
Mar 24, 2005
Location
Stokesdale-Greensboro
My riding lawnmower has me stumped. I dropped a brand new 19hp single-cylinder Briggs engine in it March 2018, and it has run perfect for 8 months. All of a sudden, it won't start. It will crank and crank, just won't fire. Pull the plug, hold it against engine, no spark.
The fact that it cranks, tells me mowers safety switches (seat, brake pedal, PTO) are not coming in to play. Maybe I'm wrong?
Just for fun, I checked fuel; No change with ether sprayed in carb. The pump flowed fuel into a Gatorade bottle, which impressively ignited when I dumped it on a flaming paper towel. Fuel shutoff solenoid clicks when I disconnect/reconnect it.
I measured 5k ohm between spark plug wire and the kill terminal on the coil. Engine still will not spark with kill wire disconnected.
Is there anything else to check before I start throwing parts at it, i.e. new coil?
 
I’ve dealt with this when it comes to a push mower where you hit something and it damages the soft steel key that locates the flywheel. If it is bent even a fraction it will not fire. Being this is a riding mower I would check the coil or some other grounding out condition.
 
Fabrik8 said:
Any oil level safety switches, etc.?
Click to expand...

hmm, I'l double check, but don't remember seeing any.
It does mention it in the engine's owners manual.

Low Oil Protection System (if equipped)


Some engines are equipped with a low oil sensor. If the oil is low, the sensor will either

activate a warning light or stop the engine.

https://www.northerntool.com/images/downloads/manuals/44651.pdf​

No rods hanging out, etc., I've been fairly gentle with it lately.

I had just changed the drive belt (had to disco/reconnect the electric blade clutch to do this), let the thing run for a few minutes to make sure its all good. I accidentally shut it down at high RPM, then tried to restart it so I could let it idle a bit before shut down...it hasn't fired since.
 
shawn said:
Does it have any connecting rods sticking out of the side of the block?
Click to expand...
it would possibly still have spark doe
 
index.php
 
Unplug the single wire off the coil. If no spark, install new coil you already ordered. (You can also continuity test the single wire to ground, key on. (Should be open key on, continuity to ground, key off) if it's grounded key on, replace ignition switch probably.
 
If it sits outside or got really wet you'll need to pull the cover and sand the magnets on the flywheel possibly
 
Briggs have a tendency to suck... I’ve had to clean up magnets on wheel after winter on pressure washing machines and I’ve also had to set the gap on magneto wheel on new engine bc factory had it over gapped and wouldnt spark! But for it to have ran previously I’d check magnets out and wiring to the engine
 
RenegadeT said:
Finally ordered a new coil Monday, installed today, fired right up.
Click to expand...
Jesus fuck thanks for the update. I have not been able to sleep for the last 2 weeks.
seriously glad you got it fixed
 
a_kelley said:
Unplug the single wire off the coil. If no spark, install new coil you already ordered. (You can also continuity test the single wire to ground, key on. (Should be open key on, continuity to ground, key off) if it's grounded key on, replace ignition switch probably.
Click to expand...
 
Unfookingbelievable.
Lil followup before the new stuff.
Feb.ish 2019, I hauled this over to Northern for warranty. They confirmed the old coil and my amazon replacement were not working. Their new coil fired it right up, life was good.

Today my son is mowing in the rain. Parks in in the shed once the lightning comes. Waits it out, fires it up, forgets ear protection, gets off, safety shuts it off. Now we have no spark again. Pulled plug and coil wire....no spark.
So I'm taking the plastic crap off to check kill wire, and I bust the the corroded positive battery cable.
It was cranking nice and fast. but maybe that was enough resistance to deliver very weak non-visible spark. Or maybe I'm being too hopeful.
15918341126699026186500421025369.jpg
 
I think your main issue is that it is a Briggs and Stratton engine. I just returned a Craftsman pressure washer that wouldn't start after storing it over the winter. In 1996 I was told that Craftsman carried two engines, Briggs and Stratton and Honda, never go for the BS. Yep, absolutely true. I don't know if it is their carburetors, their QC, or whatever else. BS will never make an engine that can be dependable...
 
What makes an ignition coil go bad?
Thurs night, I knew I wouldn't get to it fri or sat, amazon showed I could have a new one delivered on Saturday for $20. So here I am Sunday, got the new chinazon coil installed and the mower fires right up. In 2 years I've had 3 bad coils, the initial one, a second one "bad out of the box", and the third the one Northern replaced under Briggs warranty.
 
RenegadeT said:
What makes an ignition coil go bad?
Thurs night, I knew I wouldn't get to it fri or sat, amazon showed I could have a new one delivered on Saturday for $20. So here I am Sunday, got the new chinazon coil installed and the mower fires right up. In 2 years I've had 3 bad coils, the initial one, a second one "bad out of the box", and the third the one Northern replaced under Briggs warranty.
Click to expand...
Did you check the magnetic contact area on the flywheel that gives the coil signal to fire? It should not be rusted and there is a gap that it should be away from the coil. I never check my gap, was told a long time ago to use a match book cover so i just improvise. Coils can go bad from heat but I doubt thats your issue.
 
I scoth brited the magnet on flywheel, hoping to get the old coil sparking. The engine is only 2 years old and stored in shed, so there was not much rust.
I did regap the old coil with a piece of cardstock paper. The gap originally looked too close, but again no dice. Gapped the new coil same way, worked great.
 
Back
Top